Integrating large numbers of superconducting nanowire single-photon detectors with nanophotonic waveguides

Abstract

Quantum technologies and optical sensors with ultimate sensitivity require efficient counting of single photons. Superconducting nanowire single-photon detectors have set leading performance benchmarks in this regard but evolving from stand-alone fiber-coupled detectors to highly integrated receivers with large numbers of photonic channels and configurable optical functionalities has remained a challenge. Here we show how large numbers of superconducting nanowire single-photon detectors with high detection efficiency and low timing jitter can be integrated with nanophotonic circuits. The latter allow for combining photon counting capabilities of superconducting nanowires with active and passive optical control functionalities, such as switching, phase shifting and photon number resolution, which we demonstrate for leading photonic integrated circuit platforms. Broadband optical interconnects produced in 3D direct laser writing enable competitive system detection efficiency, which we can reproduce in a receiver unit that integrates 64 individually addressable superconducting nanowire single-photon detectors. We show that the system is well-suited for massively parallelized quantum key distribution, achieving secret key generation rates beyond 10 Mbit/sec in a field test. Integrating large numbers of superconducting nanowire single photon detectors with optical waveguides on configurable nanophotonic chips offers a wide range of applications in quantum communication, information processing and sensing.